ONS 15454 Reference Manual R8.5.x -- Storage Access Networking Cards

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Note: The terms "Unidirectional Path Switched Ring" and "UPSR" may appear in Cisco literature. These terms do not refer to using Cisco ONS 15xxx products in a unidirectional path switched ring configuration. Rather, these terms, as well as "Path Protected Mesh Network" and "PPMN," refer generally to Cisco's path protection feature, which may be used in any topological network configuration. Cisco does not recommend using its path protection feature in any particular topological network configuration.

Figure 6-1: FC_MR-4 Faceplate and Block Diagram

FC_MR-4 Card-Level Indicators

Table 6-1: FC_MR-4 Card-Level Indicators

The red FAIL LED indicates that the card processor is not ready. Replace the card if the red FAIL LED persists.

ACT LED (Green)

If the ACT/STBY LED is green, the card is operational and ready to carry traffic.

ACT LED (Amber)

If the ACT/STBY LED is amber, the card is rebooting.

FC_MR-4 Port-Level Indicators

Each FC_MR-4 port has a corresponding ACT/LNK LED. The ACT/LNK LED is solid green if the port is available to carry traffic, is provisioned as in-service, and is in the active mode. The ACT/LNK LED is flashing green if the port is carrying traffic. The ACT/LNK LED is steady amber if the port is not enabled and the link is connected, or if the port is enabled and the link is connected but there is a SONET/SDH transport error. The ACT/LNK LED is not lit if there is no link.

You can find the status of the card ports using the LCD screen on the ONS 15454 SDH fan-tray assembly. Use the LCD to view the status of any port or card slot; the screen displays the number and severity of alarms for a given port or slot. Refer to the Cisco ONS 15454 Troubleshooting Guide for a complete description of the alarm messages.

FC_MR-4 Compatibility

The FC_MR-4 cards can be installed in Slots 1 to 6 and 12 to 17 when used with the XC10G and XC-VXC-10G cards. When the shelf uses the XCVT card, the FC_MR-4 can be used in only the high-speed (slots 5/6 and 12/13).

The FC_MR-4 card can be provisioned as part of any valid ONS 15454 SONET/SDH network topology, such as a path protection, bidirectional line switched ring (BLSR), or linear network topologies. The FC_MR-4 card is compatible with Software Release 4.6 and greater.

FC_MR-4 Card Modes

The FC_MR-4 card can operate in two different modes:

Line rate mode-This mode is backward compatible with the Software R4.6 Line Rate mode.

The FC_MR-4 card reboots when a card mode changes (a traffic hit results). The Field Programmable Gate Array (FPGA) running on the card upgrades to the required image. However, the FPGA image in the card's flash memory is not modified.

Line-Rate Card Mode

The mapping for the line rate card mode is summarized here.

1 Gbps Fibre Channel/FICON is mapped into:

STS-24c, STS-48c

VC4-8c, VC4-16c

STS1-Xv where X is 19 to 24

STS3c-Xv where X is 6 to 8

VC4-Xv where X is 6 to 8

2 Gbps Fibre Channel/FICON is mapped into:

STS-48c

VC4-16c

STS-1-Xv where X is 37 to 48

STS-3c-Xv where X is 12 to 16

VC4-Xv where X is 12 to 16

Enhanced Card Mode

The features available in enhanced card mode are given in this section.

Automatic GFP buffers adjustment based on roundtrip latency between two SL ports

Automatic credits recovery during SONET switchovers/failures

Insulation for FC switches from any SONET switchovers; no FC fabric reconvergences for SONET failures of less than or equal to 60 ms

Differential Delay Features

The combination of VCAT, SW-LCAS, and GFP specifies how to process information for data and storage clients. The resulting operations introduce delays. Their impact depends on the type of service being delivered. For example, storage requirements call for very low latency, as opposed to traffic such as e-mail where latency variations are not critical.

With VCAT, SONET paths are grouped to aggregate bandwidth to form VCGs. Because each VCG member can follow a unique physical route through a network, there are differences in propagation delay, and possibly processing delays between members. The overall VCG propagation delay corresponds to that of the slowest member. The VCAT differential delay is the relative arrival time measurement between members of a VCG. The FC_MR-4 card is able to handle VCAT differential delay and provides these associated features:

Supports a maximum of 122 ms of delay difference between the shortest and longest paths.

String (port name) provisioning for each fiber channel and FICON interface on the FC_MR-4 card to allow the MDS Fabric Manager to create link association between a SAN port on a Cisco MDS 9000 switch and the FC_MR-4 SAN port.

Link Integrity

The link integrity features are as follows:

Data port disabled if upstream data port is not able to send over SONET/SDH transport

Link Recovery

Allows monitoring of B2B credit depletion due to SONET outage and full recovery of the credits, thus preventing the slow decay of bandwidth/throughput

Note: Distance extension and link recovery cannot be enabled at the same time.

FC_MR-4 Card Application

The FC_MR-4 card reliably transports carrier-class, private-line Fibre Channel/FICON transport service. Each FC_MR-4 card can support up to four 1-Gbps circuits or four 2-Gbps circuits. Four 1.0625-Gbps FC channels can be mapped into containers as small as STS-1 (subrate), with a minimum of STS-18c/VC4-6v for full rate. Four 2.125-Gbps FC channels can be mapped into containers as small as STS-1 (sub-rate), with a minimum of STS-36c/VC4-12v for full rate.

The FC_MR-4 card incorporates features optimized for carrier-class applications such as:

Carrier-class Fibre Channel/FICON

50 ms of switch time through SONET/SDH protection as specified in Telcordia GR-253-CORE

Note: Protection switch traffic hit times of less than 60 ms are not guaranteed with differential delay in effect.

Hitless software upgrades

Note: Hitless software upgrades are not possible with an activation from Software R5.0 to Software R6.0 or higher in enhanced card mode. This is because the FPGA must be upgraded to support differential delay in enhanced mode. Upgrades are still hitless with the line rate mode.